Answer:
A point that must lie on this line is the origin (0,0)
Step-by-step explanation:
we know that
The equation of the line in standard form is equal to

where
A is a positive integer
B and C are integer
In this problem
C=0
so

That means, that the line represent a proportional relationship between the variables x and y
Remember that in a proportional relationship the line passes through the origin
therefore
A point that must lie on this line is the origin (0,0)
We can use Pythagorean's Theorem in order to find the remaining side length
a^2+b^2=c^2
Let a be the shadow length
Let b be the height of the flagpole
Let c be the hypotenuse
28^2+b^2=35^2
784+b^2=1225
b^2=1225-784
b^2=441
b=√441
b=21
Therefore the flagpole is 21 meters tall.
Hope this helps!
Yes there is. i do not know the theorem but I know it's rule. If 2 lines intersect the same line, and they have an equal angle in the same quadrant then they are parallel. This is because their all of their angles would be equal and they are basically the same line but shifted over